pthread_mutexattr_getprioceiling man page

Prolog

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

pthread_mutexattr_getprioceiling, pthread_mutexattr_setprioceiling — get and set the prioceiling attribute of the mutex attributes object (REALTIME THREADS)

Synopsis

#include <pthread.h>

int pthread_mutexattr_getprioceiling(const pthread_mutexattr_t
    *restrict attr, int *restrict prioceiling);
int pthread_mutexattr_setprioceiling(pthread_mutexattr_t *attr,
    int prioceiling);

Description

The pthread_mutexattr_getprioceiling() and pthread_mutexattr_setprioceiling() functions, respectively, shall get and set the priority ceiling attribute of a mutex attributes object pointed to by attr which was previously created by the function pthread_mutexattr_init().

The prioceiling attribute contains the priority ceiling of initialized mutexes. The values of prioceiling are within the maximum range of priorities defined by SCHED_FIFO.

The prioceiling attribute defines the priority ceiling of initialized mutexes, which is the minimum priority level at which the critical section guarded by the mutex is executed. In order to avoid priority inversion, the priority ceiling of the mutex shall be set to a priority higher than or equal to the highest priority of all the threads that may lock that mutex. The values of prioceiling are within the maximum range of priorities defined under the SCHED_FIFO scheduling policy.

The behavior is undefined if the value specified by the attr argument to pthread_mutexattr_getprioceiling() or pthread_mutexattr_setprioceiling() does not refer to an initialized mutex attributes object.

Return Value

Upon successful completion, the pthread_mutexattr_getprioceiling() and pthread_mutexattr_setprioceiling() functions shall return zero; otherwise, an error number shall be returned to indicate the error.

Errors

These functions may fail if:

EINVAL
The value specified by prioceiling is invalid.
EPERM
The caller does not have the privilege to perform the operation.

These functions shall not return an error code of [EINTR].

The following sections are informative.

Rationale

If an implementation detects that the value specified by the attr argument to pthread_mutexattr_getprioceiling() or pthread_mutexattr_setprioceiling() does not refer to an initialized mutex attributes object, it is recommended that the function should fail and report an [EINVAL] error.

See Also

pthread_cond_destroy(), pthread_create(), pthread_mutex_destroy()

The Base Definitions volume of POSIX.1‐2008, <pthread.h>

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2013 IEEE/The Open Group POSIX Programmer's Manual